1. Field of the Invention
The present invention generally relates to an adjustable bedrest positioned under a mattress. More particularly, the invention relates to an inflatable triangular-shaped bladder for use in raising the head or feet of a user and to a microprocessor for controlling the amount of air in the bladder.
2. Description of Related Art
Adjustable beds have found widespread use beyond nonambulatory patients and are used in many homes among persons of all age groups, in particular beds that raise the head and/or feet. Among the devices used to raise the head or feet are inflatable air bladders intended for use with conventional beds. A number of patents disclose bladders for this purpose. For example, U.S. Pat. Nos. 3,392,412 and 3,606,623 to Aymer provide a bedrest having an inflatable bellows placed under a mattress and filled with compressed air. The bladder is filled with air by a conventional electric motor which is activated by a switch to turn the motor on and off.
Another adjustable bed rest is shown in U.S. Pat. No. 3,667,075 which discloses a bellows assembly placed under the mattress wherein the mattress is raised either at the head section or under the knee to different heights through the expandable bellows. The bellows assembly is activated by a motor containing three position switches that are manually turned upwardly to actuate respective spool valves. When the switches are turned downwardly, they operate respective solenoid valves.
The Cammack patent, U.S. Pat. No. 4,309,783, discloses an inflatable bladder that is triangular in shape. The bladder in Cammack includes flexible elements which extend from adjacent the apex to adjacent a sidewall of the triangle designed to limit the expansion of the bladder. These flexible elements of specific length are designed to reinforce maintenance of the general shape of the bag in its generally triangular shape. The control mechanism has two double acting rocker buttons associated respectively with valve outlets. Upon depression of a rocker button in one direction, the motor is energized at the same time that the valve outlet is opened, allowing air to be delivered to the air bag through a hose. The same rocker button rocked in the opposite direction enables air to be removed from the bag.
U.S. Pat. No. 5,170,522 to Walker discloses a foundation that has a first open top housing or recess located below a backrest plate. A first lift air bag is located in a first recess. When expanded, the first air bag has a generally triangular configuration so as to elevate the backrest plate in a generally upward inclined position. A second air lift bag is located adjacent the leg portion of the structure. When expanded, this has a generally trapezoidal configuration. An air mattress is located on top of the foundation and the air mattress is adapted to bend with the transverse plates when the plates are elevated with the first and second lift air bags. A hand control is used to control the operation of a pump to change the air pressure in the mattress and also to change the air pressure in the first and second lift air bags. The controller has air operated switches for regulating a pump to supply air to air mattresses and lift air bags. Switches also control separate solenoid valves that are used to direct to the air mattress and lift bags.
It is an object of the present invention to provide an inflatable bladder containing an interior baffle which assures that the bladder will be formed into a triangular shape for use as a bedrest. Another object of the present invention is to provide a hand held controller with a microprocessor for controlling the inflation and deflation of an inflatable bedrest. It is a further object of the present invention to provide a device for raising and lowering the head end and/or the foot end of a mattress that includes a triangular shaped inflatable bladder and a hand held microprocessor controller.
The above and other objects and advantages of the invention are achieved by the provision of an inflatable bladder, which is in general a triangular shaped structure when inflated. The invention also includes the use of a microprocessor based hand controller for inflating and deflating the bladder. The bladder and controller may be used with a conventional bed.
The bladder contains an interior baffle which is essentially is two sheets of material which extend for primarily the length of the bladder and are welded to interior walls of the bladder to form an inverse triangle inverse to the triangle formation of the bladder once it is inflated. The benefit of this interior baffle is that once the bladder is inflated, the baffle will cause the bladder to form into an appropriate triangular shape. Without this baffle, even though the overall structure of the bladder is intended to be triangular when it is inflated, the shape cannot be as precisely controlled without the baffle and the resultant bladder will form into possibly a circle or an oblong shaped object of non-triangular shape. The interior baffle wall therefore enables the structure to form more precisely into the desired triangular shape in order to perform a more effective position when inserted under the mattress in the head location of the bed.
The microprocessor based hand controller enables an individual to inflate or deflate either the bladder under the head area or the bladder under the knee area of the bed to any desired amount with a simple control. In addition, the hand controlled microprocessor permits computer programming so that the mattress can be automatically raised and lowered to different levels during different periods of time. An additional feature is that one does not need to simply continue to hold the switch down in order to raise or lower the bladder portion but instead can press a simple button after the entire hand controlled microprocessor has been preprogrammed so that any one of a number of different adjustments can be made and these can be made at any given time and preset to any given time and interval.
Thus, with the present invention there is provided a bladder and control system for raising and lowering the head and or leg area of a bed that is easy to install, simple in operation and one that may be used with a conventional bed.